From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 966B5C282D0 for ; Tue, 29 Jan 2019 15:14:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 628142184D for ; Tue, 29 Jan 2019 15:14:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="F2ynsHIn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 628142184D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KZvJjAixdh9tZqFk/eEhGZVljdexo92eQ+H+3MBOg4k=; b=F2ynsHInr0rTFT/Zacljhrt+O 4E5DGSjd7cMHWuCeY63cxrB6uW37uFbtVq3N/rIaEV3ML45ZJ6MmY58qju5hpW7ccuP2Ymi5Dtm5C pkfYmJvqK+zmqjr9SbDg3FJFOdJ8Jo8ny5Brn5qD4NndwZurOLPs3Fh9KUl0jwhly/wNk9SoIwND+ i5PFUBMDQXgSrSmwKmzM7n6hDd7pbHjDwnLAM9bSLIgg16REhaXDyd13iy37Wn9ueGTfToBLdkV6U ddcDPPtj+Ekng4riX8KzV4kQJKG+P0AZnHZ7eNVH+TMSxINw2SQQ6r707J1cdmTglw+MZw0+sO7NN 0XdSIqu6g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1goV5i-0001KI-0I; Tue, 29 Jan 2019 15:14:22 +0000 Received: from relay1-d.mail.gandi.net ([217.70.183.193]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1goV5N-0000xz-9w for linux-arm-kernel@lists.infradead.org; Tue, 29 Jan 2019 15:14:07 +0000 X-Originating-IP: 90.88.147.226 Received: from localhost (aaubervilliers-681-1-27-226.w90-88.abo.wanadoo.fr [90.88.147.226]) (Authenticated sender: maxime.ripard@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id C6AE6240007; Tue, 29 Jan 2019 15:13:48 +0000 (UTC) Date: Tue, 29 Jan 2019 16:13:48 +0100 From: Maxime Ripard To: Jagan Teki Subject: Re: [PATCH v6 11/22] clk: sunxi-ng: a64: Add minimum rate for PLL_MIPI Message-ID: <20190129151348.mh27btttsqcmeban@flea> References: <20190124195900.22620-1-jagan@amarulasolutions.com> <20190124195900.22620-12-jagan@amarulasolutions.com> <20190125212433.ni2jg3wvpyjazlxf@flea> MIME-Version: 1.0 In-Reply-To: User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190129_071402_248722_A11F4FE8 X-CRM114-Status: GOOD ( 18.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree , David Airlie , Michael Turquette , linux-sunxi , linux-kernel , dri-devel , Chen-Yu Tsai , Rob Herring , Daniel Vetter , Michael Trimarchi , linux-amarula@amarulasolutions.com, linux-clk , linux-arm-kernel Content-Type: multipart/mixed; boundary="===============1275299848126930843==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============1275299848126930843== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="sk46bbi4mwes7v4f" Content-Disposition: inline --sk46bbi4mwes7v4f Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 28, 2019 at 03:06:10PM +0530, Jagan Teki wrote: > On Sat, Jan 26, 2019 at 2:54 AM Maxime Ripard = wrote: > > > > On Fri, Jan 25, 2019 at 01:28:49AM +0530, Jagan Teki wrote: > > > Minimum PLL used for MIPI is 500MHz, as per manual, but > > > lowering the min rate by 300MHz can result proper working > > > nkms divider with the help of desired dclock rate from > > > panel driver. > > > > > > Signed-off-by: Jagan Teki > > > Acked-by: Stephen Boyd > > > > Going 200MHz below the minimum doesn't seem really reasonable. What > > is the issue that you are trying to fix here? > > > > It looks like it's picking bad dividers, but if that's the case, this > > isn't the proper fix. >=20 > As I stated in earlier patches, the whole idea is pick the desired > dclk divider based dclk rate. So the dotclock, sun4i_dclk_round_rate > is unable to get the proper dclk divider at the end, so it eventually > picking up wrong divider value and fired vblank timeout. >=20 > So, we come-up with optimal and working min_rate 300MHz in pll-mipi to > get the desired clock something like below. > [ 2.415773] [drm] No driver support for vblank timestamp query. > [ 2.424116] sun4i_dclk_round_rate: min_div =3D 4 max_div =3D 127, rate= =3D 55000000 > [ 2.424172] ideal =3D 220000000, rounded =3D 0 > [ 2.424176] ideal =3D 275000000, rounded =3D 0 > [ 2.424194] ccu_nkm_round_rate: rate =3D 330000000 > [ 2.424197] ideal =3D 330000000, rounded =3D 330000000 > [ 2.424201] sun4i_dclk_round_rate: div =3D 6 rate =3D 55000000 > [ 2.424205] sun4i_dclk_round_rate: min_div =3D 4 max_div =3D 127, rate= =3D 55000000 > [ 2.424209] ideal =3D 220000000, rounded =3D 0 > [ 2.424213] ideal =3D 275000000, rounded =3D 0 > [ 2.424230] ccu_nkm_round_rate: rate =3D 330000000 > [ 2.424233] ideal =3D 330000000, rounded =3D 330000000 > [ 2.424236] sun4i_dclk_round_rate: div =3D 6 rate =3D 55000000 > [ 2.424253] ccu_nkm_round_rate: rate =3D 330000000 > [ 2.424270] ccu_nkm_round_rate: rate =3D 330000000 > [ 2.424278] sun4i_dclk_recalc_rate: val =3D 1, rate =3D 330000000 > [ 2.424281] sun4i_dclk_recalc_rate: val =3D 1, rate =3D 330000000 > [ 2.424306] ccu_nkm_set_rate: rate =3D 330000000, parent_rate =3D 2970= 00000 > [ 2.424309] ccu_nkm_set_rate: _nkm.n =3D 5 > [ 2.424311] ccu_nkm_set_rate: _nkm.k =3D 2 > [ 2.424313] ccu_nkm_set_rate: _nkm.m =3D 9 > [ 2.424661] sun4i_dclk_set_rate div 6 > [ 2.424668] sun4i_dclk_recalc_rate: val =3D 6, rate =3D 55000000 >=20 > But look like this wouldn't valid for all other dclock rates, say BPI > panel has 30MHz clock that would failed with this logic. >=20 > On the other side Allwinner BSP calculating dclk divider based on the > SoC's. for A33 [1] it is fixed dclk divider of 4 and for A64 is is > calculated based on the bpp/lanes. It looks like the A64 has the same divider of 4: https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers= /video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c#L12 I think you're confusing it with the ratio between the pixel clock and the dotclock, called dsi_div: https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers= /video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L198 Maxime --=20 Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --sk46bbi4mwes7v4f Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXFBtrAAKCRDj7w1vZxhR xco4AQCH9Bj/Fh4K6JpkMNURQ6aa/uNB8nz26vDwypm9CjTEqQD+PvQ8bv+3ZJvs FtMPlAuAcTjEhlOwANjzj2GWxLedgws= =MpfU -----END PGP SIGNATURE----- --sk46bbi4mwes7v4f-- --===============1275299848126930843== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============1275299848126930843==--